47 24 2002 12 Ž Žx : t Sr-Nd-Pb Œ» ( ƒ p ƒ, 230026. E-mail: lsg@ustc.edu.cn) x t ¾ x Nd-Pb Œ : t xε Nd 15 ~ 21, 206 Pb/ 204 Pb<17.9, xε Nd > 10, 206 Pb/ 204 Pb>18.3. x t - xε Nd 19, 206 Pb/ 204 Pb<17.3. x p,., j Ž, x t Nd Œ Ž. ºx Ž o x, zz. Ž Žx o u. m, x x n, x x ¾,. u,.  ¾ x 2 (delamination) z ux. - Ž tx t - u. ¼ t Sr-Nd-Pb Œ p  ¾ x, x Ž  ¾ Ž( 1 S1). j Li [1] x,, x Ž Ž( 1 S2), Ž 400 km, x¹»zz., Li [1] t x. Chung [2] t n x p, o n x Sr-Nd- Pb Œ p t n, x t n., Chung [2] x x, x. Ž Žx. j, Li [1] Chung [2] x Žx (decoupling)o p - x x, j : (1) Žx ; (2) tx gš x x¹º; (3) Ž x t u x ¾ ¹º. j x p o x ¾ x. t x Sr-Nd-Pb Œ ¹ x Žx, ¹º. 1 x t ¾ x ¹ x, x [3~19]., t ¾ x Sr-Nd-Pb Œ ¾ x ¾. 1898 www.scichina.com
47 24 2002 12 1 Sr, Nd, Pb Œ x t ¾ x - (S1) Ž(S2) AB x Nd Œ 4 ux x ¾ t ¾ (,, n n tx ) ux x Sr-Nd-Pb Œ [3~19]. x 1. x (130 ~ 110 Ma), (190 ~ 160 Ma). u x x,, x (NBS-987 87 Sr/ 86 Sr = 0.710250; BCR-1 143 Nd/ 144 Nd = 0.512630; NBS981 207 Pb/ 206 Pb = 0.9142 ± 0.0015). x Sr-Nd Œ Œ Sr-Nd Œ ( 2). x Pb Œ U/Pb,. - x U-Pb Œ p ¾ µ,,, ¹º [11]. 2 t ¾ x Sr-Nd-Pb Œ 2 x t ¾ x Sr Œ, xε Nd x. t ¾ x ε Nd 15 ~ 21, x t ¾ x ε Nd 10. ε Nd >0x, ε Nd, 9.2 ~ 9.8. ˆ x Nd Œ. 2,, x t ¾ o EMm ˆ x Â. z, t ¾ e j o www.scichina.com 1899
47 24 2002 12 2 t ¾ x Sr-Nd Œ x. [3 ~ 10, 12 ~ 20]. Sr-Nd Œ [4], MORB [21] EMl ˆ x ( 2). x EMm u [8]. ε Nd x ( 2) x ˆ. t n x Œ, x t n ε Nd 206 Pb/ 204 Pb x EMl, x t n ε Nd 206 Pb/ 204 Pb x EMm, Œ x x ˆ [2]. t n o EMm [22]. t ¾ x EMl EMmx Sr-Nd Œ ƒ : (1) EMl EMm x [5,6]. t ¾ xε Nd x x ; (2) x EMl EMm z ux, x ¾ [3,4]. u x,, t ¾e xε Nd x. 2 ƒ, ¹ ƒ x x zx. º ƒ, ¹ t ε Nd x t Nd Œ x, ½. j z x¹º., t ¾e ε Nd x j x v Ž. x t ¾ x Pb Œ Sr-Nd Œ, y x, x x. x, x t ¾ x Pb Œ. 3 x t ¾ Pb Œ ( 206 Pb/ 204 Pb<17.9), x t ¾ EMmx x Pb ( 206 Pb/ 204 Pb>18.0). t n 1900 www.scichina.com
47 24 2002 12 x x Pb Œ x [2,13] ( 3)., t ¾ x Pb Œ x. 3 Ž ¾- : (1) m z- z ¾ ( ƒ ); (2) ( ƒ ); (3)  ¾ ; (4) - ¾. j,  ¾ - ¾ x. x ¾ p [23], x o [24,25],» x ; z, o t [23]., Ž ( 1 S1) [23].,, º 3 t ¾ x 207 Pb/ 204 Pb- 206 Pb/ 204 Pb 208 Pb/ 204 Pb- 206 Pb/ 204 Pb EMl, EMmˆ p Ž pš Ž [21]. [5,8,10 ~ 13, 16] www.scichina.com 1901
47 24 2002 12. U-Pb» (130 ~ 120 Ma) [26,27]. Š [3] Jahn Š [4] x n, x ˆ x Sr-Nd Œ. 2, t x Sr-Nd Œ t ¾, o EMl ˆ xâ, ε Nd ( 12 ~ 19). Š [11] - x U-Pb Œ. x 207 Pb/ 204 Pb 208 Pb/ 204 Pb, x Pb Œ ( 206 Pb/ 204 Pb<17.3) ( - ) t ¾ ( 3). x 207 Pb/ 204 Pb Th/U x 207 Pb/ 204 Pb LOMU ˆ [11]. Sr-Nd-Pb Œ, x x. x ε Nd,, xž ( 4), t x ε Nd t. x Ž x. Žx u t x Nd Œ x, x Ž j Ž 50 km ( 1 S2). 4 - Ž Ž x : x»» x Ž Žx o. Li [1] ºx x xo, - x. Ž Ž o u. ½ Li x, 3 g x : (r) x  ¾ ½., t Â, t.  ¾,  ¾ (T = 500j)x 219 ± 5 Ma [28]. ½ (210 ~ 220 Ma) [29,30], [31]. x j x. (s) Ž o ¾ x Œ x., Ž t., Ž ( )z, x Ž( Ž) 150 km. j 4 x Nd Œ ( 1 A-B) ε Nd t ¾ x 1902 www.scichina.com
47 24 2002 12  x [32,33]., x Ž t  t( ). (t) U-Pb Œ p x e m ¾ [26,34], u ½ Ž, x., x tx. t x x ¾. g, m z ux Ž o. m,, x ƒ m o [31,35], n [35], t, - -. x, x ¾ ( ), (delamination), Ž ( 5)., y ( 5). y x, ƒ x [36] g. ¹, m x m - x 5 x Ž ¹» (180 ~ 170 Ma) ¾ x 2 x t u tx.,, ( xâ ¾ )x ¾ x ( 5), xâ ¾ 170 Ma [28], - u [37]. x z. 170~160Ma x [38,39] x [40]., 1, ŽxÂ,. x Ž, Li [1] x Ž Â, x Ž x, j x Žz., ¹,  ( 1). Ãx t. 5 t www.scichina.com 1903
47 24 2002 12 x Ž x «., t Â, Žx, Ž z x u [41,42]. x x tx  x Ž x p. xƒ, ¹º,. LiZ-X ½ º, ½. j ƒ ( : 49873006) g z(g1999075503) ƒ» z(kzcxz- 107)À. 1 Li Z -X. Collision between the North and South China Blocks: A crustal-detachment model for the suturing in the region east of the Tanlu fault. Geology, 1994, 22: 739 ~ 742 2 Chung S -L. Trace element and isotope characteristics of Cenogoic basalts around the Tanlu fault with implications for the Eastern Plate Boundary between North and South China. J of Geology, 1999, 107: 301 ~ 312 3,, Hart S R, Š. z u m. - x Sr, Nd Œ p. ƒ, D, 1998, 28: 18 ~ 22 4 Jahn B -M, Wu F, Lo C -H, et al. Crust-mantle interaction induced by deep subduction of the continental crust: Geochemical and Sr-Nd isotopic evidence from post-cellisional mafic-ultramafic intrasions of the Northern Dabie complex, central China. Chem Geol, 1999, 157: 119 ~ 146 5,,, Š. t e Sr-Nd-Pb Œ. p, 2001, 30: 10 ~ 23 6 Guo F, Fan W -M, Wang Y -L, et al. Late mesogoic mafic intrusive complexes in North China Block: Constraints on the nature of subcontinental lithospheric mantle. Phys Chem Earth (A), 2001, 26: 759 ~ 771 7 t, n,, Š. t e j Œ Nd-Sr Œ p. ¾, 1997, 3: 384 ~ 395 8 t, t,. e j x 40 Ar- 39 Ar Æ. ƒ, 2001, 46(18): 1500 ~ 1508 9,,, Š.. ƒ, 2000, 30: 209 ~ 214 10,,, Š. n Sr, Nd, Pb Œ ¾., 1998, 14: 190 ~ 197 11,,, Š. - x U-Pb Œ p : - z u LOMU ˆ. ƒ, D, 2002, 32(8): 625 ~ 634 12,,, Š. x Œ p. : m, 1994. 121 ~ 131 13 p. ¾ Œ p. : ƒ m, 1995. 92 14, n, «t, Š. y n y x., 1999, 15: 116 ~ 123 15,,. n e. ( pƒ ), 1993, 5(4): 420 ~ 429 16,,, Š. n Œ x». ¾ƒ, 1999, 34(1): 59 ~ 68 17,,, Š. t n x Sr, Nd Œ, Œ p. : m, 1993. 45 ~ 46 18 t,,, Š. x Nd Œ : t ¾., 2001, 17(1): 19 ~ 27 19,,, Š. t n¾ : m. Œ Sr, Nd Œ p. p, 2001, 30 : 57 ~ 65 20 t,, O Reilly S Y, Š. ¾ Œ., 1999, 15: 217 ~ 223 21 Zindler A, Hart S R. Chemical Geodynamics. Ann Rev Earth Planet Sci, 1986, 14: 493 ~ 571 22,,. vx : e x». ƒ, 2001, 46: 1825 ~ 1831 23 Li S -G, Huang F, Nie Y -H, et al. Geochemical and Geochronological Constraints on the suture location between the North and South China Block in the Dabie orogen, Central China. Phys Chem Earth (A), 2001, 26: 655 ~ 672 24,, f, Š. x o z. ƒ, 1999, 44(13): 1452 ~ 1456 25 f,,, Š. ¾m x U-Pb. ¾, 2000, 6(1): 417 ~ 423 26,,, Š. - x U-Pb ¾. ¾, 1999, 5: 351 ~ 355 27,,, Š. - x U-Pb. ƒ, 1999, 44(19): 2110 ~ 2114 28 Li S -G, Jagoutz E, Chen Y, et al. Sm-Nd and Rb-Sr isotopic chronology and cooling history of ultrahigh pressure metamorphic rocks and their country rocks at Shuanghe in the Dabie orogen, central China. Geochem Cosmochem Acta, 2000, 64: 1077 ~ 1093 29,, ChenY-D, Š. ƒ U-Pb ¾. p, 2000, 29(3): 209 ~ 216 30,,, Š. y x Œ Æ. ƒ, 2001, 46: 748 ~ 753 1904 www.scichina.com
47 24 2002 12 31 Davies J H, Blanckenburg F V. Slab break off: A model of lithosphere detachment and its test in magmatism and deformation of collisinal orogents. Earth Planet Sci Lett, 1995, 129: 85 ~ 102 32 f,. x. ¾º», 1992, 28: 316 ~ 322 33,, n, Š.  x 40 Ar/ 39 Ar. ƒ, D, 2001, 31: 250 ~ 256 34,,, Š.  ¾ m x U-Pb Œ  x. ƒ, D, 2001, 31(12): 977 ~ 984 35 Chemenda A I, Burg J P, Mattauer M. Evolutionary model of the Himalaya-Tibet system: Geopoem based on new modeling, geological and geophysical data. Earth Planet Sci Lett, 2000, 174: 397 ~ 409 36, Â,. y. ¾, 1999, 73: 15 ~ 24 37 n,,, Š.  ¾ x, o. ƒ, 2001, 46: 1216 ~ 1219 38 Ma C -Q, Li Z -C, Ehlers C, et al. A post-collisional magmatic plumbing system: Mesogoic granitoid plutons from the Dabieshan high-pressure and ultrahigh-pressure metamorphic zone, eastcentral China. Lithos, 1998, 45: 431 ~ 456 39,, n æ. z t ¾ ¾. ƒ, D, 2000, 30(4): 355 ~ 363 40,,. - x. ƒ, 2001, 46(17): 1487 ~ 1491 41,,.. : ¾ m, 1991. 194 ~ 312 42 n,, t, Š. xe u. ¾, 1996, 70(1): 23 ~ 34 (2002-07-18 ) www.scichina.com 1905